<h1>SoundStreamBlock</h1>

<p>SoundStreamBlock contains the sound data being streamed to the Flash Player. 
Streaming sounds are played in tight synchronisation with one SoundStreamBlock 
object defining the sound for each frame displayed in a movie.</p>

<table>

<tr>
<th nowrap>Field Name</th>
<th>Type</th>
<th>Size</th>
<th>Description</th>
</tr>

<tr>
<td nowrap valign="top">type</td>
<td nowrap valign="top">unsigned bit</td>
<td nowrap valign="top" align="right">10</td>
<td>Identifies the SoundStreamBlock instruction when it is encoded. It is encoded 
with the length field as a 16-bit integer (Little-endian byte order).</td>
</tr>

<tr>
<td nowrap valign="top">length</td>
<td nowrap valign="top">unsigned bit</td>
<td nowrap valign="top" align="right">6</td>
<td>The length in bytes of the body of the instruction when it is encoded. If the length is greater 
than 62 then this field is set to 0x3F and the length is encoded using the 
extendedLength field. Encoded with the type field as a 16-bit integer.</td>
</tr>

<tr>
<td nowrap valign="top">extendedLength</td>
<td nowrap valign="top">unsigned int</td>
<td nowrap valign="top" align="right">32</td>
<td>Optional. Contains the length in bytes of the encoded instruction if it is
greater than 62 bytes. If the length is 62 bytes or less then this field is 
omitted.</td>
</tr>

<tr>
<td nowrap valign="top">soundData</td>
<td nowrap valign="top">byte</td>
<td nowrap valign="top" align="right">[n]</td>
<td>The encoded sound data for a single frame in a movie. The format for the sound 
is defined in an SoundStreamHead instruction. Sounds may be encoded using the 
PCM, NATIVE_PCM, ADPCM, MP3 or NELLYMOSER formats.</td>
</tr>

</table>

<p>When a streaming sound is played if the Flash Player cannot render the frames 
fast enough to maintain synchronisation with the sound being played then frames 
will be skipped. Normally the player will reduce the frame rate so every frame 
of a movie is played.</p>

<h2>History</h2>

<p>The SoundStreamBlock instruction represents the SoundStreamBlock tag from the Macromedia 
Flash (SWF) File Format Specification. It was introduced in Flash 1 with support for 
Uncompressed PCM encoded sounds (both Little-Endian and Big-Endian formats) and the 
compressed ADPCM format. Support for MP3 was added in Flash 3. The Nellymoser Asao
format was added in Flash 6.</p>
